[dsc] Allow multiple bpf_program and append content

[Anand Buddhdev]

On 17/01/2017 08:06, Jerry Lundström wrote:

Hi Jerry,

> Did you see that local_address can take netmasks now so you can specify
> networks?

Yes, I have noticed this feature. Thanks :) I just haven't gotten round
to updating our config files, but I will.

> See #114, your not alone with large filters :)

I didn't think we were alone. However, those of us with large filters
are in a minority.

>> I'm not a fan of introducing extra syntax parsing rules to please
>> humans. It adds code complexity and bugs for no gain.
> 
> That is a false assumption, the changes I suggested makes the least
> amount of code change, complexity and would only affect bpf_program.
> 
> The changes you've suggested would affect all options and at a very
> large increase in code and config complexity which can lead to more bugs.

Actually I'm not suggesting any changes. My preference is to leave the
config parser alone, and not make any changes to it.

I'd like to re-iterate that those of us who do have large filters, most
likely generate them from templates instead of writing them by hand, and
so there's no need for a multi-line bpf_program feature. And those who
write these by hand, most likely have small filters, and then the
multi-line feature is pointless.

Regards,
Anand